POM YUNTIANHUA CM90
POM YUNTIANHUA CM90
POM YUNTIANHUA CM90 is an engineering plastic with high stiffness, high strength and good dimensional stability. It also possesses good chemical‑resistance, wide service‑temperature range, excellent wear‑resistance and self‑lubricating property.
Main Applications
Automotive: skeleton‑type components including gears, bearings, auto‑parts, machine‑tool and instrument inner parts, such as pump components, valve parts, under‑hood components, automotive electronics and exterior auto‑parts. Electrical & electronic: gears, bearings and structural components for home appliances such as washing‑machine & juicer parts, timer assemblies, keyboards and switch parts, as well as electronic components e.g. connectors. Precision mechanical & industrial parts: high‑precision, wear‑resistant, low‑friction mechanical structural parts, including gears, bearings, cams, screws, levers, pulleys, sprockets and pipe valves. Consumer & others: daily‑use articles such as toys, sports‑equipment, zippers, lighters and buckles.
Physical Properties
| Property Category | Item | Test Standard | Typical Data | Unit |
|---|---|---|---|---|
| Physical Properties | Density | ISO 1183 | 1.41 | g/cm³ |
| Water absorption (23℃,24h) | ISO 62 | 0.60 | % | |
| MFR (190℃/2.16 kg) | ISO 1133 | 9.0 | g/10min | |
| Mechanical Properties | Tensile yield strength (23℃) | ISO 527‑2 | 64 | MPa |
| Elongation at break (23℃) | ISO 527‑2 | 35 | % | |
| Tensile modulus (23℃) | ISO 527‑2 | 2700 | MPa | |
| Flexural strength (23℃) | ISO 178 | 88 | MPa | |
| Flexural modulus (23℃) | ISO 178 | 2600 | MPa | |
| Charpy notched impact strength (23℃) | ISO 179/1eA | 6.0 | kJ/m² | |
| Thermal Properties | HDT (1.8 MPa) | ISO 75‑2/A | 95.0 | ℃ |
| Flammability | UL94 rating | UL 94 | HB | — |
Injection Molding Parameters
| Process Stage | Parameter | Recommended Range | Unit | Remarks |
|---|---|---|---|---|
| Pre‑treatment | Drying temperature | 80‑90 | ℃ | Drying recommended for better dimension & appearance, avoid bubbles/silver streaks despite low moisture absorption of 0.60 %. |
| Drying time | 3‑4 | h | ||
| Barrel temperature | Rear zone | 160‑180 | ℃ | Narrow processing window; strictly avoid＞230℃, formaldehyde gas will be generated by decomposition. |
| Middle zone | 170‑200 | ℃ | ||
| Front zone | 190‑210 | ℃ | ||
| Nozzle temperature | 180‑210 | ℃ | Slightly lower than or close to front‑zone temperature to prevent drooling. | |
| Melt temperature | 190‑210 | ℃ | Typical range for copolymer POM‑C. | |
| Mold temperature | 60‑90 | ℃ | Higher mold temperature improves crystallization, dimensional stability, surface gloss and reduces sink marks. | |
| Injection parameters | Injection pressure | Adjust by part geometry & wall thickness | — | |
| Hold‑up pressure | Proper hold‑pressure to reduce shrinkage & sink marks | — | ||
| Back pressure | Keep low | — | Excessive back‑pressure causes shear‑heating degradation. | |
| Injection speed | Medium‑to‑high | — | Slow speed causes flow marks; excessive speed brings jet mark & shear degradation. | |
| Screw speed | Moderate | rpm | Avoid excessive shear heat leading to material decomposition. | |
| Barrel residence time | ＜20‑30 | min | Short residence required to prevent thermal decomposition. | |
| Shutdown procedure | Short‑term shutdown | Drop barrel temperature to 150 | ℃ | Purge barrel thoroughly for long‑term shutdown. |
| Barrel purging material | PE / PP | — | Turn off heating, move screw forward. Must purge with PE/PP after halogen‑containing or acidic polymers to prevent violent reaction. | |
| Post‑treatment | Annealing (if required) | — | — | Thermal treatment for high‑quality parts working under non‑ambient‑service condition to release internal stress. |
Note: All data above is for reference only！
